1. Field of the Invention
The present invention relates to a system for automatically painting the external wall of a building, the system being suspended from a hoist apparatus disposed on the roof of the building and paints the outer surface of the external wall while preventing any scattering of paint mist by means of a painting hood.
2. Description of Prior Art
An example of a conventional system for automatically painting the external wall of a building by the same inventors is provided with a painting hood to prevent the scattering of paint mist is disclosed in Japanese Utility Model (Laid-Open) No. 5849/1987.
This system has the following arrangement. Flat rollers and auxiliary rollers are provided on the upper and lower edges at the end of a painting hood facing the outer surface of the external wall to be painted. The painting hood is provided with side rollers which are mounted on side edges at end thereof, which can be automatically advanced and retracted in accordance with the configuration of the surface of the wall. When the automatic painting is performed, the painting hood is brought into close contact with the outer surface of the wall to be painted and is moved laterally or horizontally along the surface of the wall to prevent the scattering of paint mist. Since the rollers are each formed of an elastic, flexible material, the rollers enable the hood to stay in contact with the wall surface, and the rollers enable smooth movement along the wall surface.
Although this conventional painting system enables automatic painting in a continuous manner, the system has several disadvantages. Since the rollers are pressed against the portion of the wall surface that is already painted, marks are formed on the painted wall surface which degrade the quality of the finished surface. Furthermore, the rollers which are formed of a flexible, elastic material become worn after repeated use, causing a gap between the rollers and the wall surface. The gap eventually results in the inadequate suppression of the scattering of the paint mist.